JUPITER, Fla. -- Now in his fourth year as Cardinals manager, Mike Matheny has been consistent in his desire to feature an element of competition in each camp. He likes that idea of players being pushed.

It's present in several ways this Spring Training, with the rotation's fifth spot, middle-relief roles and bench spots still unsettled. Yet Wednesday marked the first time in a decade that the Cardinals held their first full-squad workout with a fairly clear idea of the eight position players who, barring injury, will take the field on Opening Day.

The Cardinals returned seven starting position players and filled the right-field vacancy by acquiring Jason Heyward in November. Yadier Molina, Matt Holliday, Matt Carpenter and Jhonny Peralta have already established themselves as everyday players. Jon Jay won back the center-field job with a strong 2014 season and signed a two-year extension this offseason. Kolten Wong and Matt Adams, while both still developing, would have to slip this spring to not hang on to the starting reins at their respective positions.

Outlook: Jay, OF, STL

Outlook: Jay looks to maintain solid batting average

Jon Jay has continued to put up good numbers in the Cardinals' lineup, hitting .303 last year to go with decent defense in center field

Nevertheless, the Cardinals are still pushing the competition card.

"It's still going out there and understanding the fact that you have to earn it," Matheny said. "[If] a well-established player goes out and has a rough spring, he's probably still going to get a lot of opportunity because we know what he can do. But he's constantly fighting for that spot. We've seen too many times, even in this organization, how that can go away in a hurry."

Back in '05, the Cardinals opened spring with an infield of Albert Pujols (first base), Mark Grudzielanek (second base), David Eckstein (shortstop) and Scott Rolen (third base). Veterans Reggie Sanders, Jim Edmonds and Larry Walker covered the outfield. With Matheny's departure that previous winter, Molina entered camp ready for his first season as a full-time catcher.

Wanting to keep an open mind and knowing that injuries can erase even the best-prepared plans, the Cardinals don't intend to write anything in pen just yet.

"I just think overall maybe it's a little more competitive than meets that eye," general manager John Mozeliak said. "Obviously, we didn't bring Mark Reynolds in here to not try. He's a pretty accomplished Major League player, so he should be there to push somebody like a Matt Adams. Obviously, Jon Jay is likely going to be our center fielder, but a healthy Peter Bourjos could create a competition there as well. I think overall, yeah, you can pretty much write it in. But you can also envision how there could be some positions of interest."